1. Field of the Invention
The present invention relates to air bag devices that protect vehicle passengers from vehicle collisions, and more particularly to curtain air bag devices that protect the passengers from side vehicle collisions and method of producing the same.
2. Description of the Related Art
Hitherto, in the field of wheeled motor vehicles, various curtain air bag devices have been proposed and put into practical use. Usually, the curtain air bag device is mounted on an upper side portion of a passenger room and upon a vehicle collision (viz., side collision), an air bag of the device is rapidly expanded like a curtain in a space between a passenger (viz., a head of the passenger) and a side window thereby to protect him or her from a severe shock of the collision. One of such air bag devices is disclosed in Japanese Laid-open Patent Application (Tokkai) 2007-196856.
For clarifying the present invention, the curtain air bag device of the Laid-open patent application will be briefly discussed in the following.
The curtain air bag device of the application comprises generally an elongate air bag that includes elongate inside and outside base fabrics connected to each other at respective marginal portions to form an elongate bag and an elongate inner fabric structure that is installed in the elongate air bag and includes mutually connected first and second elongate inner fabrics. For setting the inner fabric structure in the air bag, respective front and rear ends of the first and second inner fabrics and upper and lower connecting portions of the first and second inner fabrics are connected to the inside and outside base fabrics of the air bag. With such setting of the inner fabric structure in the air bag, there are formed in the air bag a plurality of expandable chambers that are arranged in three layers. Thus, upon a vehicle collision, protection of a passenger's head is effected by at least two expanded chambers that are overlapped substantially in a direction of the collision, which brings about a satisfaction in safely protecting the passenger.